Zoom tool stitches together thousands of nanoscopic cell images

A team of molecular biologists has published a paper revealing
how its "virtual nanoscopy" method creates detailed, high
resolution images of cellular structures by "stitching" together
thousands of electron microscope photos.

Electron microscopes can magnify an image by up to 10 million
times using beams of electrons. However, the tool can only be used
to either capture a single, detailed image of part of a cell or, at
a lower resolution, a less-detailed overview of the cell. There was
no way, until now, to relate the one to the other and give a
contextual and detailed overview of the entire cell structure at
once.

In the paperVirtual nanoscopy: Generation of ultra-large high resolution
electron microscopy maps, Leiden University Medical Centre
molecular biologist Frank Faas and his team explain how they have
enabled "unbiased high resolution data access while maintaining the
lower resolution overview of the cellular context". It's a little
like Google Earth's zoom tool, but for cell biologists.

The team joined together 26,434 detailed photos of a 1.5
millimetre-long zebrafish embryo taken using an FEI Eagle CCD
camera linked up to an electron microscope. The total data of all
the photos that made up the full embryo picture amounted to 281
gigapixels, with a resolution of 16 million pixels per inch -- to
visualise just what incredible detail that resolution offers,
compare that pixel count to the 220 pixel-per-inch resolution
boasted by Apple's new Retina display Macbook Pro. Seems pretty paltry now, doesn't it. The
final image slide was created using a program specifically
developed for the task -- MyStitch extracts metadata from
transmission electron microscopy (TEM) images and uses this to pair
the images, noting any overlaps and adjusting the joins
appropriately. Images have been stitched together in a similar
manner in the past, using tools such as Adobe Photoshop, but only
on a much smaller scale. Generating a full image of a cellular
structure calls for huge amounts of time-consuming data collection,
so the team achieved its feat by automating some of the processes,
from the data-stitching down to the photo-taking.

The final image has been published at the upgraded JCB DataViewer site where interested
parties can play around with the zoom function and take in not only
the embryo, but images of mouse glomeruli, human dendritic cells
and mouse embryonic fibroblasts.

Medical professionals often zoom in on the part of a cell they
believe to be the main area of focus, or the root of a problem. By
presenting a comprehensive image, the new "virtual nanoscopy"
method ensures they get the whole picture and do not miss or
inadvertently skim over important elements.

"Virtual nanoscopy does not suffer from sparse or possibly
biased selection of regions of interest for high resolution
imaging," states the paper. "[It] provides an objective and
representative approach to record, communicate, and share data of
large areas of biological specimens at nanometre resolution."